Yamaha CLP295 Channel Messages

Using Your Instrument with Other Devices

CVP-409/407 Owner’s Manual 197

In the case of digital instruments, the audio signals are sent

through output jacks (such as [AUX OUT]) on the instrument.

The “controller” and “tone generator” in the illustration

above are equivalent to the piano in our acoustic exam-

ple. Here, the player’s performance on the keyboard is

captured as MIDI song data (see illustration below). In

order to record the audio performance on an acoustic

piano, special recording equipment is needed. How-

ever, since the instrument features a built-in sequencer

that lets you record performance data, this recording

equipment is unnecessary. Instead, your digital instru-

ment—the Clavinova—allows you to both record and

play back the data.

However, we also need a sound source to produce the

audio, which eventually comes from your speakers. The

tone generator of the instrument ﬁlls this function. The

recorded performance is reproduced by the sequencer,

playing back the song data, using a tone generator

capable of accurately producing various instrument

sounds—including that of a piano. Looked at in another

way, the relation of the sequencer and the tone genera-

tor is similar to that of the pianist and the piano—one

plays the other. Since digital instruments handle play-

back data and the actual sounds independently, we can

hear our piano performance played by another instru-

ment, such as guitar or violin.

Even though it is a single musical instrument, the instrument can

be thought of as containing several electronic components: a con-

troller, a tone generator, and a sequencer.

Finally, we’ll take a look at the actual data that gets

recorded and that serves as the basis for playing the

sounds. For example, let’s say you play a “C” quarter

note using the grand piano sound on the instrument’s

keyboard. Unlike an acoustic instrument that puts out a

resonated note, the electronic instrument puts out infor-

mation from the keyboard such as “with what voice,”

“with which key,” “about how strong,” “when was it

pressed” and “when was it released.” Then each piece

of information is changed into a number value and sent

to the tone generator. Using these numbers as a basis

for sound generation, the tone generator plays the

stored sampled note.

Example Keyboard Data

Panel operations on the instrument, such as playing the

keyboard and selecting voices, are processed and

stored as MIDI data. The auto accompaniment Styles

and Songs also consist of MIDI data.

MIDI is an acronym that stands for Musical Instrument

Digital Interface, which allows electronic musical

instruments to communicate with each other, by send-

ing and receiving compatible Note, Control Change,

Program Change and various other types of MIDI data,

or messages.

The instrument can control a MIDI device by transmit-

ting note related data and various types of controller

data. The instrument can be controlled by incoming

MIDI messages which automatically determine the tone

generator mode, select MIDI channels, voices and

effects, change parameter values and of course play the

voices speciﬁed for the various parts.

MIDI data has the following advantages over audio data:

•The amount of data is much less.

•The data can be effectively and easily edited, even to the point

of changing voices and transforming the data.

MIDI messages can be divided into two groups: Chan-

nel messages and System messages.

Channel Messages

The instrument is an electronic instrument that can han-

dle 16 MIDI channels (or reception of 32 channels for

MIDI data reception when using the [USB] terminal).

This is usually expressed as “it can play 16 instruments

at the same time.” Channel messages transmit informa-

tion such as Note ON/OFF, Program Change, for each

of the 16 channels.

Sequencer

Tone Generator

Recording and play back the performance of a digital

instrument (MIDI data)

Controller (keyboard, etc.)

Recording Playback

USB storage

device

USB storage

device

Tone generator

Sequencer

Keyboard performance (MIDI data)

Voice number (with what voice) 01 (grand piano)

Note number (with which key) 60 (C3)

Note on (when was it pressed)

and

note off (when was it released)

Timing expressed

numerically

(quarter note)

Velocity

(strength at which it was played)

120 (strong)

Connecting a Computer or USB Device/What is MIDI